Die-casting machine



May 29, 1934.

W. J. DURING El AL DIE CASTING MACHINE Filed Jan. 19, 1951 62 u L 2' 455 3 m 43 I I4 4'3 4 4-3 J2 H E 3 I 1' f0 48 C 4s 94 4:! 9 4f.

5 Sheets-Sheet 1 w 'rlvfss U l/vvenron y 1934- w. J. DURlNG ET AL1,960,992

DIE CASTING MACHINE Filed Jan. 19, 1931 5 Sheets-Sheet 2 .BY I

I W/TNESS' 3 Q W May 29, 1934. w J DURlNG ET AL 1,960,992

DIE CASTING MACHINE Filed Jan. 19, 19 3 Sheets-Sheet 3 I s 8 M m A25 1llama m3 [/7 0 lfl/z l I Mo "0 0 i rn..,i I ,3 /3/ MB 6 x ll A 2/ 4 W JI IZH B ZI I/fi'NTIIR WIT/v5 -s 8 ma Patented May 29, 1934 I Q Q UNITEDSTATES PATENT OFFICE DIE-CASTING MACHINE William J. During, Syracuse, N.Y., and Nathan Lester, Cleveland, Ohio, assignors to Precision CastingsCompany, Inc., Syracuse, N. 1., a corporation of New York ApplicationJanuary 19, 1931, Serial No. 509,758

Claims. (Cl. 22-48) This invention relates to improvements in diethe topof the furnace to form a closure for the casting machines in which avertically movable upper end of the heating chamber as 3 provided diesection operates in conjunction with a fixed in the furnace.-

die section. One side of the furnace is provided with an One of theobjects of this invention is to proopening 4 in communication with thechamber 3, duce an apparatus adapted to form castings from and is closedby a suitable cover or door 5 hingedaluminum, brass or other materials,wherein the 1y connected as at 6, or otherwise removably se- 'moltenmetal is fed by vacuum and atmospheric cured to the furnace for thepurpose of permitpressure from a crucible or melting pot into a ting theopening of the chamber3 and the placing suitable delivery or pressurepot. of a crucible or melting pot as 'l in said chamber. 65

Another object is to provide means for auto A suitable means may beprovided for melting the matically controlling the flow of the moltenmetal metal contained in the melting pot I, such as the into thepressure pot for each casting operation gas burner 8 built at aconvenient location in the to substantially the amount required to fillthe wall of the furnace 1. I

Upon the cover plate 2 is mounted a fixed die 70 A further object is toprovide means for ejectplate 9 which, in this instance, is maintained ining the molten metal from the pressure pot into substantially parallelspaced relation with the a suitable die or mold under very highpressure. cover plate by means of integral downwardly pro- A stillfurther object is to provide means whereiecting sides 10. The die plate9'is fixedly secured by the surplus metal remaining in the delivery tothe cover plate 2 by means of bolts or screws 75 pct, after a castinghas been formed, will be 11 which pass through openings in laterallyautomatically ejected from the delivery pot into formed flanges 12provided at the lower edge of the melting pot as the casting is beingejected the sides 10 and screw-threaded in the cover from the diecavity. plate 2.

$ Still another object is to provide simple and The fixed die plate 9,in this instance, extends 89 eflicient means whereby the various movingparts over substantially the entire surface of the cover of theapparatus may be easily and positively plate 2 and is provided at oneend thereof with controlled by the operation of a single lever. adownwardly projecting wall or flange 13 adapted Other objects andadvantages will more fully to form one head plate of a cylinder 14 whichis l appear from the following description, taken in positioned adjacentthe outer face of the wall 13 connection with the accompanying drawingsin to extend outwardly therefrom in a horizontal which: plane.

Figure 1 is a front elevation of an apparatus The outer end of thecylinder 14 is closed by embodying the various features of thisinvention, a cover plate 15 which, together with the cylinder certainparts being shown in section. The appa- 14, are secured to the wall 13by means of suitable ratus is illustrated in the casting position. boltsor screws lfi which pass through suitable Figure 2 is a verticallongitudinal sectional openings in the plate 15 and are screw-threadedview of the apparatus shown in Figure 1, with the in the wall 13. Apiston 17 is mounted for lon-v various parts illustrated in theinoperative or gitudinal reciprocative movement in the cylinder 10icasting ejecting position. 14 and is provided with a piston rod 18 whichex- 95 Figure 3 is an enlarged detail horizontal sectends outwardly fromthe cylinder 4 through a tional view taken substantially on line 33,Figsuitable opening 19 provided in the wall 13 and ure 1. has the outerend thereof connected by a link Figure 4 is an enlarged detail sectionalview 20-to a plunger 21 mounted for longitudinal retaken on line 4-4,Figure 2. ciprocative movement in the pressure chamber .100

Figure 5 is an enlarged vertical longitudinal 22 formed in a pressure ordelivery not 23. sectional view through the control valve, and The link20 is removably connected with the taken subst n i lly li Figure 1.piston rod 18 and the plunger 21 for the purpose Figure 6 is a verticalsectional view taken of permitting the link .tobe quickly and easily 60through the vacuum control valve in the plane removed for the purpose ofsubstituting links of 1 of the line 6--6, Figure 5. greater or lesslengths.

The apparatus, as illustrated in the drawings, The delivery pct 23, inthis instance, is secured consists of a furnace 1 formed of any suitableto the underface of the fixed die plate 9 in any material. The furnaceis provided with a cover suitable manner as by screws 24. The pressureplate 2 secured in any well-known manner to chamber 22 in the deliverypct 23 has the side no 1 walls thereof disposed in a substantiallyvertical plane, while the end thereof adjacent the cylinder 14 is closedby the plunger 21.

It may now be understood that the molten metal contained in the chamber22, may be forced under very high pressure by the action of plunger 21into the die cavity. For instance, by supplying fluid, as oil, to theouter end of cylinder 14 at 3,000 pounds pressure per squareinch andwith the piston 17 four inches in diameter the pressure exerted on theplunger 21 is approximately 37,500 pounds per square inch, and with theplunger formed 1% inches square, it follows that the plunger normallyexerts approximately 12,250 pounds per square inch on the molten metalas the die cavity becomes filled.

The lower wall of the delivery pot 23 is provided with an aperture orport 25 extending therethrough with the outer side surface thereofsubstantially in alignment with the inner end of the plunger 21 whensaid plunger is in its extreme outer position. 7 a

A feed tube 26 is secured to the lower face of the delivery pot 23 bymeans of flanged clamps 27 engaging a flange 28 provided at the upperend of the feed tube 26 and secured by bolts 29 or their equivalent tothe delivery pct 23. The feed tube 26 extends downwardly from thedelivery pct 23 in a vertical plane through a suitable opening 30provided in the cover plate 2 and has the upper end thereof inregistration with the port 25 and the lower end positioned to extendsome distance into the melting pot 7.

The forward or outer end of the chamber 22 is in communication with anaperture or nozzle 32 formed in a nozzle block 33 positioned in asuitable opening formed in the fixed die plate 9 and which is incommunication with a gate or sprue die opening 34 provided in the fixeddie section 35 secured by any suitable means as screws 36 to the upperface of the die-supporting plate 9.

The die section 35 forms one portion of a die member 38, the otherportion of which, as 39, is secured in any suitable manner to a movabledie supporting plate 40 slidably mounted for longitudinal reciprocativemovement upon a plurality of, in this instance four, vertically disposedspacing rods 41. I

These rods 41 are each disposed at substantially the corner of animaginary square and have the lower ends thereof secured to the fixeddie supporting plate 9, while the upper ends of these rods arescrew-threaded and support a cylinder plate 42 which is adjustablysecured to the rods 41 by means of nuts 43 screw-threaded on the rods 41and positioned one adjacent the upper and lower face of said plate.

The movable die-supporting plate 40 is operably connected with thecylinder plate 42 by a toggle mechanism 44 which, in this instance,consists of a pair of links 45 pivotally connected at 46 in transversespaced relation to respective upwardly extending lugs 47 secured to ormade integral with the upper face of the movable die plate 40. The outerends of these links 45 are pivotally connected at 48 with one end ofrespecarms in spaced relation during the operation thereof.

Each of the links 51 have the free or outer edges thereof madeconcentric with the respective pivots 52 and provided with gear teeth 55which are adapted to mesh with respective sides of a double-faced rackmember 57 which is adjustably secured to one end of a piston rod 58 bymeans of nuts 59 screw-threaded on the end of the rod 58 and positionedone adjacent opposite faces of an outwardly extending lug 60 secured toor made integral with the rack 57.

The piston rod 58 extends upwardly in a vertical plane from the rack 57through asuitable opening 61 provided in one of the end plates 62 of acylinder 63 and is secured to a suitable piston 64 mounted forlongitudinal reciprocative movement in the cylinder 63.

The cylinder end plate, 62 is mounted upon the upper end of upwardlyextending bracket 42' secured to or made integral with the cylinderplate 42. The outer or upper end of the cylinder 43 is also providedwith an end plate 65 which, to-= gether with the cylinder 63 and endplate 62, are securedto the bracket 42' and to each other by means ofbolts or screws 68 which pass through registering openings in the endplates 61 and 65 and are screw-threaded in the upper end of the bracket42'.

Each of the links 51, in this instance, is provided with a web or lug51' adapted, when the toggle mechanism is in the collapsed position, toengage the outer edge of the adjacent portion of the respective arms 49for limiting the collapsible movement of the toggle, as illustrated moreclearly in Figure 2.

The adjacent ends of the links 45 and arms 49 are each provided withabutting shoulders 45' and 49 respectively, adapted when the togglemechanism is in the extended position, to engage each other and assistin maintaining the pivots 46, 48, 54, 50 and 52 in the same straightline.

The manipulation of the toggle mechanism 44, is for the purpose of'moving the die section 39 into and out of casting relation with theother die section 35, and this is accomplished through the medium of therack 57 as it is moved vertically by the piston 64 which. causescorresponding rocking movement of the co-acting links 51.

This rocking movement of the links 51 will rock the arms 49 about theirpivotal connection 54 with the head 55 and thereby move the links fromthe extended position to the collapsed position or vice versa, which inturn, will cause a corresponding vertical movement of the movable dieplate 40 and die section 39.

Secured to the cross head 55 in any suitable manner as by screws 67 is aplate 68 which has secured thereto a pair of downwardly projecting rods69 which extend through suitable openings in the die-supporting plate 40and have their lower ends positioned in a recess 70 formed in theunderface of the die plate 40 and secured to a second ejector plate '71similar to the plate 68.

To the ejector plate 71 is secured a plurality of, in this instance two,ejector pins 72 which extend downwardly from the ejector plate 71through suitable openings in the die section 39 and have, when the diesections 39 and 35 are in casting relation with each other, the innerends thereof in registration with the die cavity to form a smoothcontinuous surface therein, as illustrated more clearly in Figure 1.

The ejector pin 72, being connected with the cross head 55, will travela less distance during the upward movement of the movable die plate 40than the die section 39 due to the pivotal ac--' tion of the arms 49 andlinks 45 which will cause the lower ends of the ejector pins 42 toextend below the lower face of the die section 39 when said section isin its extreme upper position, and thereby cause the ejection of thecasting from the die section during said upward movement, as illustratedin Figure 2.

The die section 39 is also provided with an annular recess 74 extendinginwardly from the upper face thereof to within a relatively shortdistance of the wall of the die cavity, and a second annular recess as75 smaller in diameter than the recess 74 and which extends from therecess '74 to the die cavity. In these recesses 74 and '15 is slidablymounted, a pin 76 which has the upper end thereof provided with anenlarged,annular sage 34 when the die sections 35 and 39 are in castingrelation.

The lower end of the pin 76 has, in this instance, a conical formationadapted to extend a short distance into the gate 34 but is of slightlyless diameter than said gate so as to provide a very slight passagewaybetween the wall of the gate and the adjacent portion of the pin '76,for

the purpose of permitting passage of air between said pin and walls ofthe gate when a vacuum is produced in the die cavity, but at the sametime, prevent the passage of molten metal past-the end of the pin 76 dueto the solidifying of the metal as it enters between the pin-and gatedue to the,

relatively small passageway therebetween, as will be hereinafter morefully explained.

The vacuum in the die cavity may be produced in any suitable manner whenthe die sections 35 and 39 are in casting relation, and for thispurpose, the flxed die section 35 is provided with a pair of passages 80which extend inwardly from one side of the die in parallel spacedrelation, and have the inner ends thereof terminating in an upwardlyprojecting portion or port 80' in communication with the upper face ofthe die between the die cavity and the outer face of said die.

The upper face of the fixed die section 35 is also provided with aslight recess as 81 extending between respective ports 80' andtheadjacent portion of the die cavity so that when the die sections 35 and39 are in contact with each other, the recesses 81 will form a veryshallow passage between the respective ports 80' and the die cavity forpermitting the air to be drawn therethrough in producing the vacuum inthe die cavity and pressure chamber 22.

The outer ends of each of the passages 80 are connected with a conduit82 which extends outwardly therefrom a short distance and is connectedwith a common conduit 83, which is connected at the opposite end thereofwith a suitable air' control valve. 84 adapted to automatically connectthe die cavity with a suitable vacuum-' producing means during theoperation of the casting apparatus, in a manner hereinafter more ing inthe chamber 22 after the casting has been formed, will be collectedatthe forward end thereof and it is, therefore, necessary that thissurplus metal be removed from the pressure cham- ;ber before anothercasting is formed, and for this purpose, the forward or inner end of theplunger 21. is provided with a vertically disposed dove-tail slot 86 inwhich the metal in the pot will collect during the casting operation andafter the casting has been formed, the metal remaining in the pot willsolidify due to the small quantity thereof, and thereby be connectedwith the plunger 21 so that as the plunger 21 is moved outwardly to itsoriginal position, the metal remaining in the chamber 22 will be drawnoutwardly with the plunger and broken from contact with the sprue at itssmallest diameter, that is, where the aperture 32 communicates withv thepressure chamber 22.

As the plunger 21 reaches its outer position, the forward end thereofcontaining the dove-tail slot will be in registration with the port 25provided in the lower wall of the delivery pct 23. The solidified metalconnected with the plunger 21 may now be forced downwardly through theport 25 and feed tube 26 into the melting pot '7, and for this purpose,a suitable ejector plate 87 adapted to be received in the slot 86, ismounted for vertical reciprocative movement in a slot 88 provided in thefixed die plate 9 at one side of the die 35 and in registration with theslot 86 when the plunger 21 is in its extreme outer position.

The upper end of the ejector plate 87 is posi tioned, in this instance,in a slot 89 formed in the upper face of the fixed die plate. 9 andwhich extends longitudinally of said plate in an outward direction fromthe vertical ejector plate slot 88, and has the outer vertical facethereof provided with .a series of gear teeth 90 adapted to have meshingengagement with similar teeth formed on one end of a rock arm 91 whichis rotatably mounted upona pin 92 which extends through an openingprovided in the arm 91 intermediate the ends thereof and has its endssecured in the opposite walls of the slot89.

The opposite or outer end of the arm 91 is also provided with gear teethadapted to have meshing engagement with similar teeth provided on thelower end of an upwardly extending vertically disposed ejector rod 94.

The lower end of the rod 94 is slidably mounted in a suitable aperture95 provided in the upper face of the plate 9 adjacent the outer end ofthe slot 89, while the upper end of the rod 94 extends upwardly througha suitable opening provided in an outwardly extending horizontallydisposed arm 96 secured to or made integral with the adjacent verticalside of the movable die-supporting plate 40, as illustrated more clearlyin Figure 2.

Two sets of nuts as 97 are screw-threaded upon the rod 94, the setsbeing positioned at opposite sides of the arm 96 in such a relation tothe movement of said arm as to cause the arm to produce the desiredrocking movement of the rock arm 91 and the ejector plate 8'7 as the movable die plate40 approaches the limit of its upward or downwardmovement. In other words, 0

when die sections 35 and 32 are in casting relation, the lowerpositioned nuts 9? are so ar raimed on the rod that the arm 93 connectedwith the plate so will cause the rod or to be in its lowermost positionwhich will cause the ejector plate 87 to be in its extreme upperposition with the lower end face thereof in registration with the lowerface of the fixed die plate 3 so as to form a smooth continuous surfaceover the plunger 21 for permitting said plunger to moved inwardly forejecting the molten metal from the pressure chamber 32.

The distance between the upper and lower positioned nuts 9'? is suchthat as the movable die supporting plate 10 approaches the limit of itsupward movement and after the plunger 21 has been returned to itsextreme outer position, the arm 86 will engage the upper positioned nuts97 to cause the upward movement of the rod 94 and, therefore, thedownward movement of the ejector plate 87, due to the action of the rockarm 91 which will force any metal connected with the inner end of theplunger 21 from contact with said plunger and through the port 25 andfeed tube 26 into the melting pot 7 where it will again become molten asit drops into the molten metal contained in the pot 7.

Each of the pistons 17 and 64 is actuated in its respective cylindersHand 63 by fluid, as oil under pressure, and for this purpose, each ofthese cylinders is connected by respective conduits with a suitablecontrol valve 100 which, in turn, is connected with a suitable sourcefor supplying fluid under pressure, not shown. For instance, cylinder 141s provided with ports 1G1 and 102 provided in the end plate 15 and wall13 respectively andwhich are in communication with respective ends ofsaid cylinders.

The ports 101 and 102 have their outer ends connected by respectiveconduits 103 and 104 with the control valve 100. Likewise the cylinder63 is provided with a pair of ports 105 and 106 formed respectively inend plates 62 and 65 with the inner ends thereof in communication withthe adjacent ends of the cylinder 63. The outer ends of these ports areconnected by respective conduits 107 and 108 with the. control valve100.

The control valve 100, in this instance, consists of a substantiallyrectangular body member 110 secured in any suitable manner as by screws111 to the upper face of a bracket 112 secured to or made integral withone of the vertical walls of the furnace 1.

The valve body 110 is provided with a cylindrical opening or chamber 113which extends longitudinal therethroug'h. The ends of the chamber 113are closed by suitable end plates 114 and 115 secured by screws 116 ortheir equivalent to respective ends of the body 110. The upper portionof the body 110 is provided with an inlet port 117 which has the innerend thereof communicated with the chamber 113 by means of an annularrecess' 118 formed in the wall of the chamber 113.

The outer end of the port 117 may be connected in any suitable manner asby a conduit 113 with the source of fluid supply. The body 110 is alsoprovided with a plurality of, in this instance four, control ports 120arranged in pairs with a pair positioned at each side of the inlet port117.

These control ports 120 are connected with the chamber 113 by respectiveannular recesses 121 formed similar to the recess 118 in the wall of thechamber 113 and spaced equal distances from each other and from therecess 118 so as to form respective inwardly projecting flanges 122 hechamber 113, said flanges being 1 J equal width.

the chamber 113 adjacent the cover plates 11% and 125 are also providedwith annular recesses 123 which are in communica- The piston 126 isprovided near the ends thereof with outwardly extending annular flanges12; of substantially the same diameter as the chamber 113 and having awidth eoual to the width of the chamber flanges 122 so as to form afluid-tight connection between the piston and the wall of the chamber113 where these flanged portions 122 occur for the purpose of separatingcertain groups of recesses 121.

The distance between the piston flanges 12? in this instance, is equalto the distance between the outer face of the outer positioned recess121 of the chamber 113 and the outer face of the recess 118 positionedat the opposite side of said recess to that at which the first-mentionedrecess 121 occurs.

The piston 126 is moved longitudinally through the chamber 113 by meansof a piston rod 128 which has one end thereof connected with said pistonand extends outwardly through a suitable opening as 129 provided in oneof the end plates as 115 and has the outer end thereof connected with asuitable rack member 130 slidably mounted in a suitable guide 131provided in a bracket 132 secured to the valve-supporting bracket 112.

This rack 130 may be actuated by any suitable means such as a lever 133pivotally connected intermediate its ends as at 134 to the bracket 132in a plane above the rack 130. The lower end of the arm 133 is madeconcentric with the pivot 134 and provided with gear teeth 135 adaptedto have meshing engagement with the teeth of the rack 130. The lever 133may be maintained at predetermined positions for the purpose ofmaintaining the piston 126 in certain relation with the control portsand for this purpose, the lever 133 is provided with a plunger 136slidably mounted in a suitable slot 137 provided in the lever 133 andadapted to engage in a slot 133 provided in the upper portion of thebracket 132 above the pivot 134 and made concentric with said pivot.

The slot 138 is also provided with a plurality of, in this instancethree, radially disposed grooves or notches 139 formed in the upperperiphery thereof adapted to receive a lateral projection formed on theplunger 136. The plunger 136 may be .yieldingly maintained in contactwith the notches 139 by any suitable means such as a rod 140 having oneend connected with said plunger and the other end extending upwardlythrough a suitable opening in the lever 133 and terminating in aninwardly extending annular recess 141 provided in the upper end of lever133 and connected with a suitable nut 142.

A spring 143 is positioned in the recess 141 between the nut 142 and thelower end of said recess for yieldingly maintaining the plunger 136 inits upper position in contact with the groove 139.

The vacuum control valve or, in this instance,

is operably connected with the piston rod 126 by means or a crank arm145 having one end thereof connected with a stem 146 which is connectedto or made integral with the valve rotor 147 while the other end thereofis operably connected with a grooved collar 148 secured to the rod 128so that when the piston 126 is moved in the chamber 113 for causing thepiston 64 to be moved downwardly for the purpose of bringing the diesection 39 into casting engagement with the die section 35, the valve 84will be opened for the purpose of connecting the die cavity with themeans for producing a vacuum in the die cavity and pressure chamber 22,and when the piston 126 in the chamber 113 is again moved for thepurpose of admitting fluid to the head end of the cylinder 14 to causethe piston 17 to be moved inwardly in the cylinder 14 'to cause theplunger 21 to force the molten metal from the pressure chamber 22 intothe die cavity, the valve 84 will be closed for cutting oil theconnection between the die cavity and the vacuum-producing means.

It will be noted by referring to Figure 5, that the conduit 103 for thecylinder 14 is connected with the control port 120 positioned farthestfrom the inlet port 117 adjacent the outer end of the chamber 113 andthat the conduit 104 for the cylinder 114 is connected with the controlport 120 adjacent the inlet port 11! and positioned at the opposite sidethereof tothat at which the port for the conduit 103 is located.

The conduit 107 for the cylinder 53 is connected with "the control port120 positioned farthest from the inlet port 117 and adjacent the innerthe control valve 100 in the position illustrated in Figure 5 and thevacuum control valve 84, as illustrated in said Figure 5, in the closedposition, it is evident that the rod ends of each oi the cylinders 14and 63 are connected by the control valve 100 with the inlet conduit 119and, therefore, with the source of fluid supply under pressure and thatthe head ends of these cylinders are connected by the respectiveconduits 103 and'l03 with the exhaust conduit 125.

"Now, by manipulating the lever 133 to move the valve piston'126inwardly the distance between two adjacent control ports 120, the rodend of the cylinder 63 will be connected with the exhaust conduit 125while the head end of said cylinder will be cut oil from the exhaustconduit 125 and connected with the inlet conduit 119 which will admitfluid under pressure to the upper end of the cylinder 63 and cause thedownward movement of the piston 64 contained there- This downwardmovement of the piston 64 will cause the toggle mechanism 44 to be movedto the extended position which will carry the movable die-supportingplate 40 and die section 39 connected therewith downwardly to bring thedie section 39 into casting relation with the fixed die section 35, asillustrated in Figure 1. At the same time, the vacuum control valve 84will be opened and connect thedie chamber and there- As the molten metalcontained in the melting pot I must be maintained above the inlet to thefeed tube 26 or substantially at a level indicated by the dotted line X,the molten metal contained in the pot '7 will be forced by atmosphericpressure upwardly through the feed tube 26 into the pressure chamber 22and as the chamber 22 becomes fllled with the molten metal, the metalwill gradually rise until it reaches the stud '76 and as the metal flowsbetween the stud 76 and the wall of the gate 34, the metal will becomesolidifled therein due to the relatively small passageway, ashereinbeiore described, thereby cutting oif the vacuum and discontinuingthe flow or metal upwardly through the i'eed tube 26.

As this takesplace, the lever 133 is again manipulated to cause thei'urther outer movement of the piston 126 in the control valve 100 forthe purpose of disconnecting the rod end of the cylinder 14 with thefluid under pressure and connecting it with the exhaust conduit 125 andconnecting the head end 01' saidcylinder with the source of fluid supplyand, at the same time, close the vacuum control valve 84 for theconnection of the die cavity of the vacuum-creating means. This willcause the inward movement of the piston 1'7 and plunger 21 connectedtherewith, and as the part 25 in the delivery pct 23 is closed by theplunger, the remainder of the molten metal contained in the pressurechamber 22 will be forced under very great pressure upwarde 1y throughthe gate 34 which'will cause the stud 76 to be moved upwardly againstthe action of the spring '17 and permit the molten metal to flow intothe die cavity.

Owing to-the relatively narrow depths of the recesses 81 connecting thedie cavity with the vacuum ports 80', the'molten metal flowing into saidrecesses fromthe. die cavity, will immediately become solidified andthereby close said recesses and prevent the molten metal from flowinginto andclosing the vacuum-ports 80. As the die cavity becomes filled,the surplus metal remaining in the pressure chamber 22 will becomesolidifled and connected with the plunger 21, due to the metal, engagingthe dove-tail slot 86 in said plunger.

The lever 33 which is, at this time, in the position illustrated bydotted lines in Figure 5, will now be moved in the opposite directionfrom the previous movement to return-the piston 126 to its originalposition at the inner end of the chamber 113. This inward movement 01the piston 126 will first reverse the fluid pressure in the cylinder 114which will causejthe outward movement 130 of the piston l'l'and thereturn of the plunger 21 to its original outermost position in thepressure pct 22 with the inner end of said plunger in registration withthe port 25 and feed tube 26.

' As this movement of the piston 126 is continued, the rod end of thecylinder 63 will be connected with the source of fluid pressure whichwill cause the upward movement of the piston 64 contained therein andthe consequent moving of the toggle mechanism 44 from the extended tothe collapsed position which will cause the separation of the diesections 35 and 39 and the ejection of. the casting from the die cavityby the action of the ejector pin '72 in the manner hereinbeforedescribed. I

As the die section 39 and movable die-supporting plate 40 approaches itsextreme upper position, the arm 96 will engage the upper positioned nuts9'1 and move the rod 94 upwardly thereby rocking the rock arm 91 aboutthe pivot 92 and forcing the ejector plate 87 downwardly to the positionillustrated in Figure 2, thereby causing the surplus solidified metalconnected with the plunger 21 to be moved downwardly out of engagementwith the slot 86 and thru the port 25 and feed tube 26 into the meltingpot 7.

As the control valve is again manipulated for repeating this cycle ofoperations, the ejector plate 3'7 will again be returned to itsuppermost position by the arm 96 coming in contact with the lowerpositioned nuts 97 as the plate to and die section 39 connectedtherewith, approach their lowermost position with the die section 39 incontact with the die section 35.

It will be noted that the vacuum control valve 84 is so operated, thatwhen the die sections are in contact with each other, the valve will bein the open position for connecting the die cavity with thevacuum-producing means, and 'that when the piston 126 is moved in thecontrol valve 100 for causing the upward movement of the piston 64 toraise the movable die section 39 out of engagement with the section 35,the valve 84 willbe closed by the action of the rod 128 upon the arm145, thereby closing the vacuum line as the die cavity is opened. Thevacuum line will thus remain closed until the piston 126 is againoperated to cause the closing of the die 38 when the valve 84 will againbe opened for connecting the closed die cavity with the vacuum-producingmeans.

Although there is shown and described the preferred embodiment of thisinvention, it is not desired to be limited to the exact form andrelation of the parts shown, as various changes may readily be madewithout departing from the spirit of this invention as set forth in theappended claims.

We claim:

1. In a die-casting machine in combination with a die member and amelting pot, of a pressure chamber mounted in casting relation with thedie member, metal-conveying means connecting the chamber with theinterior of the pot,

pressure means connected with the die adapted to produce a vacuum in thedie and chamber to cause molten metal contained in the pot to fiow intothe pressure chamber, and means for ejecting the metal from the chamberinto said die.

2. In a die-casting machine the combination with a die member and amelting pot, of a pressure chamber mounted in casting relation with thedie member, metal-conveying means connecting the chamber with theinterior of the pot, pressure means adapted to cause molten metalcontained in the pot to fiow into the pressure chamber, means forautomatically limiting the amount of metal flowing into the chamber,means for ejecting the molten metal from the chamber into the die cavityto form a casting, and

separate means for ejecting the surplus metal re-- casting is formedfrom said chamber into the pot.

4L In a die-casting machine the combination with a die member and amelting pot, of a pres-'- sure chamber mounted in casting relation withthe die, means for feeding molten metal from the weapon pot into saidchamber, a plunger mounted in the chamber, means for actuating theplunger to eject the moiten metal from the chamber into the die to forma casting, and means for ejecting the sur- 7 plus metal remaining in thechamber after the casting is formed from said chamber into the pot.

5. In a die-casting machine the combination with a die member, and amelting pot, of a pressure chamber mounted in casting relation with thedie, means for feeding molten metal from the pot into said chamber, aplunger mounted for reciprocative movement in the chamber and normallypositioned at one end thereof, means for feeding molten metal from themelting pot into the pressure chamber, means for reciprocating theplunger to eject the molten metal from the chamber into the die to forma casting, said plunger having means adapted to engage the surplus metalremaining in the chamber after the casting has been formed to cause saidsurplus metal to move with the plunger to the normal position thereof,and means adapted, when the plunger is in the normal position, to ejectsaid surplus metal from the chamber into said pot.

6. In a die-casting machine the combination with a die member and amelting pot, of a pressure chamber mounted in casting relation with thedie member, metal-conveying means connecting the chamber with theinterior of the melting pot, means adapted to produce a vacuum in thedie cavity and chamber, for causing molten metal contained in the pot tofiow into the pressure chamber, and means connected with the die forlimiting the amount of metal flowing into the chamber.

7. In a die-casting machine the combination with a die member comprisingfixed and movable sections, and a melting pot, of a pressure chambermounted in casting relation with one of said die section's,metal-conveying means connecting 1 the chamber with the interior of themelting pot, a vacuum line connected with one of the die sectionsadapted to produce a vacuum in the die cavity, pressure chamber andmetal-conveying means for causing molten metal to flow into the chamberwhen the die sections are in contact with each other, and means forautomatically closing said vacuum line when the die sections areseparated.

8. In a die-casting machine the combination with a die member comprisingfixed and movable sections, and a melting pot, of a pressure chambermounted in casting relation with one of said die sections,metal-conveying means connecting the chamber with the interior of themelting pot, means adapted to produce a vacuum in thedie cavity,pressure chamber and metal-conveying means for causing molten metalcontained in the pot to fiow into the pressure chamber, means forautomatically limiting the amount of metal fiowing into the chamber,means for ejecting the molten metal from the pressure chamber into thedie to form a casting, means for ejecting the casting from the diesections, and means for automatically ejecting the surplus metalremaining in the chamber after the casting has been formed from thechamber into the pot as the casting is ejected.-

9. In a die-casting machine the combination with a die member comprisingfixed and movable sections, and a melting pot, of a pressure chambermounted in casting relation with one of said sections, means for feedingthe molten metal from the pot into said chamber, means for ejecting themolten metal from the chamber into the Ill Ill

d e to form a casting, means for separating the 156 die sections toeject the casting, and means automatically actuated by the separation ofthe die sections for ejecting the surplus metal contained in the chamberafter the casting has been formed from the chamber into the melting pot.

10. In a die-casting machine, the combination with a die member havingan inlet opening and a melting pot of a pressure chamber mounted incasting relation with the die member, metal-conveying means connectingthe chamber with the interior of the pot, pressure means secured to thedie adapted to cause molten metal contained chamber, and spring-actuatedmeans for automatically varying the size of the die inlet opening forpreventing metal flowing into the die as the chamber becomes fil1ed..

12. In a die-casting machine, the combination with a melting pot and apressure chamber adapted to receive molten metal from the pot, of a diemember having an inlet opening in casting relation with said pressurechamber, pres.- sure means adapted to cause molten metal to flow fromthe pot into the pressure chamber under a lesser pressure for fillingthe chamber, and from the chamber into the die cavity under a greaterpressure, and means for automatically varying the size of the die inletopening for preventing the flow of metal into the die cavity during thefilling of the chamber and permitting the flow of metal into the diecavity as the metal is forced from the chamber. 7

13. In a die-casting machine, the combination with a melting pot, of apressurechamber adapt-' ed to receive molten metal from the melting pot,

and pressure-chamber for causing molten metal contained in the pot toflow into said chamber, means for ejecting the molten metal from thechamber into the die cavity, and spring-actuated means associated withsaid inlet opening for preventing molten metal being drawn into the diecavity by suction and adapted to permit the flow of the molten metalinto the die cavity during the action of the. ejecting means.

14. In a die-casting machine, the combination with a die member and apressure chamber mounted in casting relation with said die, of a plungermounted for reciprocative movement in said chamber, means forreciprocating the plunger to eject the molten metal from the chamber.into the die to form a casting, said plunger having means adapted toengage the surplus metal remaining in the chamber after the casting hasbeen formed to cause said surplus metal to move with the plunger to theinitial position, an ejector plate mounted for reciprocative movementinto the chamber for ejecting the surplus metal from said plunger, andmeans operated by a movable member of the die-casting machine forautomatically actuating the ejector plate when the plunger is in theinitial position for ejecting the surplus metal from said plunger.

15. In a die-casting machine, the combination with a sectional diemember and a pressure chamber mounted in casting relation with said die,of a plunger mounted for reciprocative movement in said chamber, meansfor reciprocating the plunger to eject the molten metal from'the chamberinto the die to form a .casting, said plunger having means adapted toengage the surplus metal remaining in the chamber after the casting hasbeen formed to cause said metal to move with the plunger to the initialposition, means for separating the die sections to eject a casting, anejector plate mounted for reciprocative movement into the chamber, andmeans con- .necting the ejector plate with one of the die sectionswhereby said ejector plate will be actuated by said die sections duringthe said separating movement to eject the surplus metal from saidplunger.

WILLIAM J. DURING. NATHAN LESTER.

